Public issue detail

Runaway CPU investigation for x86_64-linux-gnu-ld.bfd: unknown userspace loop at bfd_hash_lookup

x86_64-linux-gnu-ld.bfd is stuck in a likely unclassified userspace loop: 20.88% of sampled CPU passed through bfd_hash_lookup, with repeated thread backtraces show 1 thread(s) around 0x00007f3e33f25687 in __GI__IO_flush_all () from target:<path>.

highpackage: binutils-x86-64-linux-gnusource: binutilsscore: 106reports: 1

Last seen: 2026-10-02 08:58 UTC. Public JSON: /v1/issues/01a0fbd5-dd14-7700-8fc7-e7f71eb95e13

Technical snapshot

This is the clearest retained userspace thread cluster Fixer captured while the process was spinning.

Representative thread backtrace

  • Command: /usr/bin/ld -plugin /usr/libexec/gcc/x86_64-linux-gnu/14/liblto_plugin.so -plugin-opt=/usr/libexec/gcc/x86_64-linux-gnu/14/lto-wrapper -plugin-opt=-fresolution=/tmp/ccFcAN5u.res -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s -plugin-opt=-pass-through=-lc -plugin-opt=-pass-through=-lgcc -plugin-opt=-pass-through=-lgcc_s --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu --as-needed -shared -o postgis-3.7.so /usr/lib/gcc/x86_64-linux-gnu/14/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/14/crtbeginS.o -L/usr/local/lib -L/usr/local/lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/14 -L/usr/lib/gcc/x86_64-linux-gnu/14/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/14/../../../../lib -L/lib/x86_64-linux-gnu -L/lib/../lib -L/usr/lib/x86_64-linux-gnu -L/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/14/../../.. postgis_module.o lwgeom_accum.o lwgeom_union.o lwgeom_spheroid.o lwgeom_ogc.o lwgeom_functions_analytic.o lwgeom_functions_basic.o lwgeom_inout.o lwgeom_btree.o lwgeom_box.o lwgeom_box3d.o lwgeom_geos.o lwgeom_geos_predicates.o lwgeom_geos_prepared.o lwgeom_geos_clean.o lwgeom_geos_relatematch.o lwgeom_generate_grid.o lwgeom_export.o lwgeom_in_gml.o lwgeom_in_kml.o lwgeom_in_marc21.o lwgeom_out_marc21.o lwgeom_in_geohash.o lwgeom_in_geojson.o lwgeom_in_encoded_polyline.o lwgeom_triggers.o lwgeom_dump.o lwgeom_dumppoints.o lwgeom_nurbs_functions.o lwgeom_functions_lrs.o lwgeom_functions_temporal.o lwgeom_rectree.o lwgeom_itree.o lwgeom_sqlmm.o lwgeom_transform.o lwgeom_window.o gserialized_typmod.o gserialized_gist_2d.o gserialized_gist_nd.o gserialized_supportfn.o gserialized_spgist_2d.o gserialized_spgist_3d.o gserialized_spgist_nd.o brin_2d.o brin_nd.o brin_common.o gserialized_estimate.o geography_inout.o geography_btree.o geography_centroid.o geography_measurement.o geography_measurement_trees.o geometry_inout.o postgis_libprotobuf.o vector_tile.pb-c.o geobuf.pb-c.o mvt.o lwgeom_out_mvt.o geobuf.o lwgeom_out_geobuf.o lwgeom_out_geojson.o flatgeobuf.o lwgeom_in_flatgeobuf.o lwgeom_out_flatgeobuf.o lwgeom_remove_irrelevant_points_for_view.o lwgeom_remove_small_parts.o postgis_legacy.o -lm ../deps/wagyu/libwagyu.la -lstdc++ ../deps/flatgeobuf/libflatgeobuf.la -lstdc++ ../libpgcommon/libpgcommon.a ../liblwgeom/.libs/liblwgeom.a -lgeos_c -lproj -ljson-c -lprotobuf-c -lxml2 -lgmp -lSFCGAL -lgmpxx --exclude-libs ALL -lm -lgcc --push-state --as-needed -lgcc_s --pop-state -lc -lgcc --push-state --as-needed -lgcc_s --pop-state /usr/lib/gcc/x86_64-linux-gnu/14/crtendS.o /usr/lib/gcc/x86_64-linux-gnu/14/../../../x86_64-linux-gnu/crtn.o
  • Why Fixer classified it this way: The process is demonstrably CPU-hot, but the current syscall and symbol sample does not point to a single dominant loop family yet.
  • Thread summary: thread backtraces show 1 thread(s) around 0x00007f3e33f25687 in __GI__IO_flush_all () from target:<path>
  • Contention signals: gdb-stderr: gdb: warning: Couldn't determine a path for the index cache directory. warning: Target and debugger are in different PID namespaces; thread lists and other data are likely unreliable. Connect to gdbserver inside the container. warning: Expected absolute pathname for libpthread in the inferior, but got target:<path> warning: Unable to find libthread_db matching inferior's thread library, thread debugging will not be available.
  • Repeated loop: read
  • Top syscalls: read x1
  • Package: binutils-x86-64-linux-gnu 2.47-6
  • Kernel: 7.1.8+deb14.1-amd64
  • Distribution: debian
0x00007f3e33f25687 in __GI__IO_flush_all () from target:<path>
0x00007f3e33f256ad in __GI__IO_flush_all () from target:<path>
0x00007f3e33f99ea6 in read () from target:<path>
0x00007f3e33f20861 in _IO_file_underflow () from target:<path>
0x00007f3e33f22beb in _IO_default_uflow () from target:<path>
0x00007f3e33f158ca in _IO_getline_info () from target:<path>
0x00007f3e33f1470a in fgets () from target:<path>
0x00007f3e33d98045 in ?? () from target:<path>

Possible duplicates

These are suggestions based on sanitized trigram similarity plus structured fields like package, subsystem, classification, and wait site. They are not auto-merged.

Runaway CPU investigation for git: unknown userspace loop at adler32_z

possible duplicate

git is stuck in a likely unclassified userspace loop: 5.95% of sampled CPU passed through adler32_z, with repeated thread backtraces show 1 thread(s) around 0x00007f9b54a5bdbb in ?? () from target:<path> and 1 thread(s) around 0x00007f9b54a5bdbb in ?? () from target:<path>.

highpackage: gitsource: gitscore: 106reports: 1similarity: 75%

Why this looks related: same classification, same subsystem, same wait site

Last seen: 2026-10-03 03:35 UTC. Public page: /issues/019f77a0-05b9-7551-9a82-40564740cf6d. Public JSON: /v1/issues/019f77a0-05b9-7551-9a82-40564740cf6d

Published attempts

No public attempts have been published for this issue yet.

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